This application claims a foreign priority date of German application 199 64 131.5, filed on Nov. 22, 1999, and the contents of that application is incorporated herein by reference.
This invention relates to a rotary knob device, or rotary switch, having a key function for manipulating control elements of a type including a hollow rotary knob which can be rotated to manipulate a first electrical control element and a key mounted in the rotary knob which can be linearly move within the rotary knob to manipulate a second electrical control element.
Rotary knob devices having a key function which are part of a rotary switch and/or a rotary controller are used in operating units, for example in automotive engineering.
Such a rotary knob is disclosed in German patent document 196 36 643 C1, where keying is performed at an end face of a top part of a rotary knob. The keying itself is performed centrally by additional switch mechanisms. When the rotary knob is rotated, the key is rotated as is a symbol on a top part of the key. This is a disadvantage, particularly when the symbol on the key should always remain horizontally in the same position. Another problem arises when central illumination of the function of the key is to be performed in addition to central contacting.
It is an object of this invention to provide a rotary knob device having a key in a rotary knob which remains horizontal even when the rotary knob is rotated. Another partial object is to provide a structure which allows a central illumination of the key along with central electrical contacting when keying.
According to principles of this invention, a rotary knob device having a key function includes a hollow rotary knob which can be rotated to manipulate a first electrical control element, a key mounted in the rotary knob which can be linearly move within the rotary knob to manipulate a second electrical control element and a holder which supports both the rotary knob and the key such that each can be moved on the holder separately from the other.
This invention is based on the idea of structuring a holder for supporting a rotary knob and a key in the rotary knob to be functionally separated from one another so that the key is not also rotated when the rotary knob is rotated. This holder is the structural connection between the rotary knob and the key. The rotational adjustment is transmitted through the rotary knob, while the key-function adjustment is carried out separately through the key. For central illumination and central contacting of the key at the same time, a flexible switch push member having a central bore is provided with electrical contacts mounted around it, preferably in a ring arrangement. Light needed for illumination can be introduced through the bore into the key.
Additional advantageous embodiments are also described.
Accordingly, a mating component of the rotary knob is movably mounted on the holder while the key is securely connected directly to the holder. The advantage here is that the key does not require additional alignment with a base plate or circuit board because the rotary switch can be designed as a compact individual part. A mounting of the rotary switch device in a panel may also be accomplished by the holder.
However, the holder may also be fixedly mounted on the mating component of the rotary knob in the rotary switch device or it may be part of the mating component.
The torque may be transmitted either directly or indirectly, with a variable-film potentiometer plate being mounted on the mating component of the rotary knob for direct transmission, while peripheral teeth are.provided on the mating component for an indirect transmission so that rotation is transmitted non-centrally to an electronic component.
Advantages of the proposed solution include, in addition to retaining the horizontal position of the key and the key symbol, the fact that a central homogeneous illumination of the key symbol and a central contacting beneath the key are accomplished independently of the rotational adjustment of the rotary knob of the rotary switch or the rotary control.